The present invention relates to a surroundings monitoring apparatus for an automotive vehicle having a monitoring means such as a radar, and more particularly to a surroundings monitoring apparatus for an automotive vehicle for detecting a road geography such as a road radius of curvature in accordance with positions of vehicles around the subject vehicle detected by the radar of the moving vehicle.
For instance, Japanese Patent Application Laid-Open No. Hei 6-68398 discloses a conventional apparatus. In case of this conventional apparatus, the road geography is predicted in accordance with the movement and the relative position of the vehicles that are travelling continuously in line with the subject vehicle.
In the conventional apparatus, since the road geography (road radius of curvature) is predicted in accordance with the movement and the relative position of the plurality of vehicles that are travelling continuously in line, it is necessary to detect the plurality of the vehicles and it is also necessary to detect the movement of the vehicles, disadvantageously.
Also, the movement of the vehicles does not always follow the road geography. In some cases, the vehicles may take a movement different from the road geography due to the lane change.